Interplay MAM SOM Value

We are working with a customer who has Interplay MAM. When querying the metadata for some assets, we get values for the SOM (start of media) field that are greater than 2^31 and are not sure how to interpret these. According to the documentaiton we have, SOM is a value in milliseconds, so a SOM of 2603509709 corresponds to over 30 days. Are we interpreting this correctly? Is that field actually an unsigned ingteger?